More from WebMD

Sept. 28, 2007 -- Farmers and teachers have an increased risk of dying from
autoimmune diseases, but waitresses, bookkeepers, and teachers’ aides do not,
new research shows.

In the largest study ever to examine the occupations of people who die from
systemic autoimmune diseases like
rheumatoid arthritis, scleroderma, and lupus, researchers reviewed death
certificates from the mid-1980s to the late 1990s.

More than 300,000 death certificates from 26 states were reviewed, including
50,000 deaths due to systemic autoimmune disease.

The findings do not prove a link between any single occupation and
autoimmune disease. But they do offer intriguing clues that could serve as a
jumping off point for future research, researcher Laura Gold tells WebMD.

In farming, for example, the increase in risk was seen among farmers who
worked primarily with crops, but not among those worked mostly with
livestock.

“We can’t explain this,” she says. “We really need to look at questions like
this more closely in future studies that include more detailed occupational
history.”

Occupation and Autoimmune Disease

More than 8 million Americans are believed to have autoimmune diseases, a
catchall term for some 40 different conditions. The common link between
diseases like rheumatoid arthritis, scleroderma, lupus, multiple sclerosis, and
Crohn’s disease is that the body attacks its own cells.

The causes of this are largely unknown, but genetic, infectious, and
environmental influences are all believed to play some role. And the incidence
of most autoimmune diseases is much higher among women than men.

Previous studies have suggested a link between some systemic autoimmune
diseases and certain occupations, including farming and teaching.

In the newly published study, farmers and secondary school teachers were
each found to have a 30% increased risk for dying from systemic autoimmune
diseases.

Bank tellers, special education teachers, and mining machine operators were
among those also at increased risk.

Firefighters had twice the risk of death from scleroderma compared with
other occupations, but their overall risk of dying from systemic autoimmune
diseases was not increased.

Younger age, being female, and being African-American were all associated
with a greater risk of dying of lupus, and white race and male sex were
associated with a greater likelihood of dying from rheumatoid arthritis.

While some occupations involving exposure to the public -- such as teaching
and nursing -- were associated with an increased risk of dying from a systemic
autoimmune disease, others -- such as restaurant server and child care worker
-- were not.

Support for Environmental Role

The increases in risk for most occupations were modest, with no single job
showing a dramatic increase in risk for death from systemic autoimmune
disease.

Rheumatologist Michael Lockshin, MD, questions the use of death certificates
as a method for tracking autoimmune disease incidence.

“Most of these diseases are not highly lethal or death is often attributed
to other causes,” he says.

But he agrees the study adds support to the idea that environmental
exposures play a role in diseases like rheumatoid arthritis, lupus, and
scleroderma.

Lockshin is a professor of medicine and ob-gyn at Weill-Cornell Medical
College in New York City.

“The hope is that if we understand the steps necessary to cause these
illnesses we may be able to influence these steps,” he says